If they gonna up the seal for GC leve, please also raise up the seal from chocobo escort and also the provision mission too!
It is just not this method that are slow, actually, every method have been far too slow to build seal.

-Supply mission :
You gather 1 cobalt ore for them, and they reward you "5 seal" only... (consider 1 ore per gather nowadays, this is 2x slower seal/rate then what OP method) The woolen cloth which worth 5k in market now, only reward you "5 seal" too... not worth it.

-Chocobo escrot :
First, the condition that require 4 + members to win make it hard to form PT. It also act like behest, so you can only do it once for 30 min. But only reward for 225 seal? 15 min is the mission and another 15 min is waiting time, this is horror. They don't give you enough time to spend that 15 min with GC leve too. (consider you need time to walk in and out)

-GC leve :
just like the OP says, why must wait so long to finish it?

The seal rate are balance as it is, but no matter which method you try, all of them are slow. IMO, chocobo escort should have at least 400 seal, because of the condition that need 4 members and wait every 30 min. Or else, there is no encouragement for anybody to form PT there. GC leve should allow players to finish up if they manage to kill quick enough. And in the end, if those two get raise up, the slowest method which is from miner and botanist should get at 2x seal..

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FFXIV : ARR all instance boss gameplay video can be found here..http://www.youtube.com/user/Arikameow/videos?shelf_index=0&sort=dd&view=0